Ext.onReady(function() {
			var loader = new Ext.tree.TreeLoader({
						url : "js/demo/treedata0909.js"
					});
			var root = new Ext.tree.AsyncTreeNode({
						id : "root",
						text : "根节点",
						loader : loader
					});
			var tree = new Ext.tree.TreePanel({
						renderTo : "hello",
						root : root,
						width : 100
					});
		});